The present invention is directed to a socket device which is adjustable to accommodate differently sized bolts and nuts. Therefore, the present invention is useful in mechanically driving both standard and metric sized nuts and bolts over a broad continuous range of sizes. As such, the present invention may be employed in place of a plurality of non-adjustable sockets that are normally sold as sets wherein each member of the set has a different, non-adjustable size. Furthermore, the inventive concept and implementation of the present invention finds application as a hand operated adjustable wrench.
One of the most commonly used tools for any mechanic is that tool known as a wrench and socket set. Typically, this tool assembly includes various ratchet drivers, straight bar drivers, length and swivel adapters as well as a plurality of cylindrical sockets organized as a set of differently sized members that accommodate differently sized nuts and bolts. These sets are usually sold as standard "English" sets or metric sets. While such sets are an invaluable tool for mechanics and while such sets have definite advantages in that each socket has a relatively small diametric size, these sets nonetheless have distinct disadvantages. Since each socket is non-adjustable, it is necessary for the mechanic to carry anywhere from 16 to 32 separate pieces to allow for the wide variety of nuts and bolts which are encountered during mechanical activities. Hence, where a number of differently sized nuts and bolts are employed in a particular piece of machinery or equipment, the mechanic often finds it necessary to keep interchanging these sockets on the socket driver. Otherwise, the mechanic must have several different duplicate drivers. The continual need to change sockets on a single driver can result in substantial lost time and concomitant expense. In addition, it is easy for a mechanic to misplace a socket which again leads to lost time and frustration. The need for duplicate drivers unnecessarily increases the expense of a set of tools.
Other disadvantages are also present in traditional socket sets where a person needs to store a set of tools in a compact storage location for emergency use. Examples of such needs include automobile and vehicle emergency kits which are commonly stowed in a trunk or other storage compartment of a vehicle and in the boating industry where it is desirable to carry a small but versatile tool set either on the boat or accompanying the boat trailer. In such applications, complete socket sets prove very bulky; with the decreasing size of automobiles and storage compartments associated therewith, the practicality of sets as part of an emergency tool kit becomes less certain. As a result of these disadvantages, there has been a longfelt need for an adjustable socket which may be used with traditional socket drivers yet which allows a fairly wide range of adjustable size and which may thus accommodate both standard and metric sized nuts and bolts.
Prior to the present invention, others have sought to satisfy this need and have approached the problem of constructing an adjustable socket in a manner different from that of the present invention. For example, U.S. Pat. No. 3,385,142 issued May 28, 1968 to Cunningham shows an adjustable socket wherein a pair of jaw elements are attached to slide racks which are provided with gear teeth. The socket body includes a transverse opening provided with an axially oriented gear so that one slide rack may be inserted in either side of the gear which may be turned by an adjusting wheel to move the jaw elements together and apart. Thus, the jaw members are freely suspended, and are only supported by the interraction of the slide rack and drive gear. Similarly, U.S. Pat. No. 4,136,588 issued Jan. 30, 1979 to Roder shows an adjustable socket wherein a pair of jaw elements are suspended by slide racks which are inserted into an opening in the socket body and are driven by helical gears to move toward and away from one another. On each of these two patents, the jaw elements are only minimally supported and can be subject to damage resulting from the substantial torques encountered when the socket drives a nut structure.
Other prior art patents are directed to adjustable sockets in the form of chuck assemblies wherein a plurality of small jaws are movable on inclined surfaces toward and away from one another over a small degree of adjustment. Examples of such chuck assemblies are shown in U.S. Pat. No. 164,658 issued Jun. 22, 1875 to Powers, U.S. Pat. No. 2,582,444 issued Jan. 15, 1952 to Lucht and U.S. Pat. No. 4,213,355 issued Jul. 22, 1980 to Colvin.
While the above-cited patents describe adjustable socket or socket-type structures, these apparatus have apparently not received wide spread use. Accordingly, there remains a need for an inexpensive adjustable socket that is constructed of a relative few number of parts so that it is easy to manufacture and assemble. There is a further need for such an adjustable socket which has enhanced mechanical strength and which is adjustable over a wide range of nut structure sizes. The present invention is directed to meeting these needs.